package agenda;

import java.util.Collection;

public abstract class Agenda {

	private static Agenda INSTANCE;

	public static Agenda getInstance() {
		if (INSTANCE == null) {
			INSTANCE = new AgendaMapa();
		}
		return INSTANCE;
	}

	public abstract boolean adicionar(Contato c);

	public abstract boolean remover(String telefone);

	public abstract Contato buscar(String telefone);

	public abstract Collection<Contato> getContatos();
}
